The first thing you might notice is the roller-coaster nature of the inflation-adjusted salaries in the chart above. This is caused by pay increases that outpaced inflation in a particular year followed by static salaries failing to keep up with inflation over time — indicated by an effective salary decrease compared to the economy.

Actual decreases in the dollar amount of congressional pay were very rare, as the table below shows.

It’s important to remember that the expense of living in, say, 1855 was very different from what it costs today, so a direct comparison of that year’s inflation-adjusted salary of $78,000 with 2012’s $174,000 might not be valid. For example, the cost of renting a place to live in today’s District of Columbia, where money is power, is likely quite different from the days of the mid-19th century, when the sparsely populated city was a literal backwater. And, of course, there was no income tax in those days.